Résumé | The Institute for Marine Dynamics (IMD) maintains an extensive set of facilities, which are used for model marine vessel and offshore structure testing. As part of these facilities, sophisticated instrumentation and control systems are used to reproduce the environment and the functionality of these vessels and structures. In early 1997, IMD began the development of a Dynamic Positioning (DP) System for model vessels. A DP system is a closed-loop control system that is used to automatically control a vessel's thrusters in order to maintain a station of speechified track. The control system senses changes in position and heading which are due to the environmental forces acting upon the vessel; i.e. waves, wind and current. IMD has conducted two model tests which have utilized the DP system described in this report: the first was and extensive set of tests involving the Terra Nova FPSO (Floating Production, Storage and Offloading) vessel and the second was an unanchored semi-submersible. This paper will detail the design rationale, and some of the techniques utilized in the IMD DP system. |
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